Pancreatic cancer is one of the most fatal human cancers and continues to be a major unsolved health problem. The goal of this study was to estimate the independent effects and interactions between cigarette smoking and diabetes on the risk of pancreatic cancer in Korean male population. Cigarette smoking and the risk of incidence and death from pancreatic cancer were examined in a 10-year prospective cohort study of 446,407 Korean men aged 40 to 65 years who received health insurance from the National Health Insurance Corporation and who had a medical evaluation in 1992. Relative risks (RR) and 95% confidence intervals (CI) were calculated using a Cox proportional hazards model after adjusting for age, body mass index, exercise and alcohol use. Current smoking was associated with an increased risk of incidence (RR = 1.7, 95% CI = 1.6-1.9) and mortality (RR = 1.6, 95% CI = 1.4-1.7) from pancreatic cancer. The RR for pancreatic cancer increased with both duration and amount of smoking. Diabetes was also associated with an increased risk of both incidence (RR = 1.8, 95% CI = 1.5-2.2) and mortality (RR = 1.7, 95% CI = 1.4-2.1) from pancreatic cancer. There was no interaction between smoking and fasting serum glucose in terms of pancreatic cancer risk. Thus, our prospective study has demonstrated that cigarette smoking and elevated fasting serum glucose are independently associated with an increased risk of pancreatic cancer in a large cohort of Korean males.